How do we teach about and into Islam in Flemish and Dutch schools? This is the leading question of this special issue of Religie & Samenleving. Its relevance must be understood against recent societal developments (secularization, increasing religious diversity) as well as against pedagogical-didactical developments about 'teaching about', 'teaching into' and 'teaching from' religion in governmental and non-governmental (denominational) schools. This introductory essay elaborates on the historical and legal background of formal Islamic religious education in Belgium (Flanders) and in the Netherlands. Hereto, we first outline the constitutional frameworks in both countries, in which the provision of government-subsidized religious education should fall. Subsequently, we describe the organization of Islamic religious education, which in the Netherlands is mainly offered at Islamic schools, while in Belgium it is a subject facilitated by the government in official schools. We also show how Catholic schools in Flanders have reflected on a suitable offer for the increasing number of pupils with a Muslim background in these schools. We end our introduction by showing how in recent years, teacher education institutions in both countries have invested in preparing their students for teaching about or in Islam.